DST means 'Daylight Saving Time'. The Daylight Saving Time has been in use in some countries like United States, Canada, Brazil, Australia and also in Europe. Its goal is to make the best use of daylight hours by shifting the clocks forward in the Spring and backward in the Fall. In Europe, Daylight Saving Time is known as 'Summer Time'. The correct spelling is Daylight Saving Time, not Daylight Savings Time.